St. John's Red Storm Paris Horne (C) puts up a shot past the West Virgina Mountaineers defense in the first half at Madison Square GardenJASON SZENES/ NY POST

The St. John’s players could hear West Virginia coach Bob Huggins yelling at his team from down the hall during halftime.

“It was the usual stuff,” Mountaineers star guard Da’Sean Butler said with a laugh. “He was telling us what we needed to do — and what would happen if we didn’t do it.”

What they needed to do: switch to a 1-3-1 zone to pick up the defensive intensity, insert veteran Joe Mazzulla for his hardworking influence, and get the ball to Butler.

No. 6 West Virginia did all that in the second half Saturday to rally from a 16-point deficit and beat the Red Storm 79-60.

Butler scored a season-high 33 points, hitting all seven 3-point attempts. He was 2 of 7 from the field in the first half, 7 of 11 after the break.

The Mountaineers (19-3, 8-2 Big East) trailed 45-32 more than 6 minutes into the second half before scoring 16 straight points to take the lead for good.

Wellington Smith scored the first eight points of the run with two 3-pointers sandwiched around a putback.

Then Butler took over. He had four 3-pointers — plus an old-fashioned three-point play — in just over 5 minutes, and suddenly a potential upset was transformed into a comfortable victory. His seven 3-pointers were a career high.

“I don’t know about 3s, but (Huggins) wanted me to be aggressive,” Butler said, “and he set up some plays for me.”

West Virginia has won 10 straight against the Red Storm (12-10, 2-8).

“It’s always good when the other four guys are looking for Da’Sean,” Huggins said. “That makes us better.”

Huggins wasn’t sure what the past tense of the word “sleepwalk” is, just that it described his team’s first-half performance. West Virginia hit three of its first seven shots to take a 10-4 lead. The Mountaineers were 4 of 22 the rest of the half, scoring just nine points over a stretch of nearly 16 minutes.

The St. John’s defense had a lot to do with it, forcing seven turnovers and blocking three shots as the Red Storm took a 33-19 lead into the final minute of the half. But West Virginia wasn’t helping itself, missing several layups and making just three of its first nine free-throw attempts.

“Generally when you miss 2-, 3-footers and free throws, it’s a sign you’re not really ready to play,” Huggins said.

Enter Mazzulla. The guard averages just 1.8 points following his scoreless outing Saturday and didn’t get off the bench in the first half. Huggins wasn’t even sure he’d be able to play that morning after Mazzulla sprained his ankle Friday, an injury coaches initially feared was a broken foot.

Less than a minute into the second half, the coach decided it was worth seeing what Mazzulla could do. Huggins isn’t sure he’s ever had a player who can change a game so much without scoring.

“He just changes the intensity level of the game,” Huggins said. “He plays so hard. He plays with such great passion.”

The zone slowed down the game, St. John’s coach Norm Roberts said.

“It’s not something you can really simulate in practice because of their length,” he said.

The Red Storm have lost five in a row.

Holding a 14-point lead, they had a chance to run down the clock almost to halftime, but Dwight Hardy took a quick 3-pointer and missed. Then Anthony Mason Jr. fouled Butler on a 3-point attempt, and he hit all three foul shots to pull the Mountaineers within 33-22 at the break.

The 22 points were still the fewest West Virginia scored in the first half this season. The Mountaineers had 57 in the second half.

Justin Burrell came off the bench to score 10 points and pull down seven rebounds in the first half for St. John’s, but had a quiet second half.

Mason hit a jumper to give St. John’s a 13-point lead early in the second half. One possession later, he went to the locker room with a dislocated right middle finger. By the time he returned with 10:55 left, the Mountaineers were within 45-43.

And Huggins wouldn’t have to follow through on his halftime threats. As Butler explained: “You sit when it’s game time, then in practice, you run.”